# Tag Info

## Hot answers tagged voltage

5

LVTTL is Low Voltage Transistor-Transistor Logic. In general, the term "TTL" is used for a digital signal. The "Low Voltage" part is special, the ATmega32U4 switches from low to high (and vice versa) at low voltages. Just as it is written. For example, when the ATmega32U4 runs at 5V, then: VILmax = 0.2 * 5 - 0.1 = 0.9 V. VIHmin = 0.2 * 5 + 0.9 = 1.9 V. ...

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You can make -5 V if you use an external power source, like in the circuit below (untested). Connect the GND (-) from the Arduino to the +5V from the External (5V) source, than 0V will be the GND (with respect to the Arduino), but the GND of the external source will be -5V with respect to the Arduino. I only used the resistors to get no short circuits, you ...

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It's actually very simple, and it indeed does involve using PWM. PWM is just a signal being on for a percentage of a predefined period. That percentage is also, when the PWM signal is averaged out, equivalent to a percentage of the peak voltage of the PWM signal. So if you take a PWM signal and use it to switch a higher power source (say, through a P-...

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The Arduino Uno has no on-board battery. The dc barrel jack is provided to give you more options to power the Uno, which is handy for stand-alone applications (without USB-connection to a computer) and/or battery powered applications. It can also supply more current than the USB-connection, which can be necessary when using shields. The current taken from ...

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Here is my try at this: if your voltage source doesn't mind sinking something like 150 µA, you could try something like this: simulate this circuit – Schematic created using CircuitLab This should map the input range [−70 mV, +50 mV] to [0.04 V, 4.06 V].

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The Arduno UNO SMD R2 uses an MCP33269 not an LM1117. What you have is probably some cheap Chinese clone of the Arduino, and in that case the regulator will be the cheapest Chinese copy of the LM1117 available. It's impossible to tell what the specs of that specific chip are. Suffice it to say, though, that the specs of the chip are pretty much irrelevant ...

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Note: Since all vendors (checked Mouser, Octopart, and Sparkfun) link to the L298 datasheet when listing the L298N I will assume they are reasonably equivalent. I will assume that the "12V-35V input pin" is the V_S pin, despite that label. There are only two supply pins on the L298 with the following electrical characteristics: V_S, Supply Voltage, pin 4, ...

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When measuring a voltage that is higher than the maximum rating, the voltage of interest is tied to ground with a voltage divider. When measuring a negative voltage, you instead have to tie the voltage of interest to the positive supply voltage (study the answers to this question). In theory you can use the internal pullup to spare one resistor, but I would ...

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You need to add an external 3.3V voltage regulator. You can get these quite cheap on eBay (etc) as a module - some even come in a breadboard friendly format. Power it from the 5V from the Arduino, then power your MAX4466. However, the MAX4466 can run at up to 5.5V, so I fail to see why you think you need 3.3V.

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As others have said, an Arduino pin can't handle 12V, and can't handle anywhere near 10A of current directly. A digital pin on an Arduino is limited to 20mA, or 1/500 as much current as you need, at 5V, which is less than half the voltage you need. If you try to connect 12V to a pin on an Arduino pin you will almost certainly destroy that pin, and may ...

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I guess that you are showing the voltages there directly calculated from analogRead() and that you connected the AC voltage directly to the analog input (and it's ground with the Arduino's ground). The reference for every communication/voltage measurement/digital input is ground. Naturally the Arduino can only measure voltages inside of it's own supplied ...

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Multimeters are designed to provide a stable response. It would be averaging the readings. As far as the difference in voltage reading, if you are using the Arduino board as is the default is to assume a reference voltage for the A/D as being 5.0 volts.(for your calculations) That may not be the case. Also there may be a tolerance issue on the measurement ...

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A RC filter will create a slow slewrate. simulate this circuit – Schematic created using CircuitLab The circuit creates this signal: A slow rising signal and a fast falling signal can be created with an extra transistor (the signal will be inverted). simulate this circuit For a linear rising and falling edge, a resistor network with a few digital ...

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By "ramp", it seems that you mean a square wave with sloping rather than vertical edges between + and -. Can you clarify the question further: do the sloping parts need to be linear? Direct synthesis of the waveform could be done using the digital output ports and an R2R ladder, as suggested in the comments. Each PWM timer output of the AVR can control ...

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You need to amplify your signal and add 2.5V as a "virtual ground" for the amplification. This gets a little tricky, since you need a low-impedance VCC/2 source to feed the amplifier as a virtual ground. This would require a unity-gain buffer fed from a voltage divider: simulate this circuit – Schematic created using CircuitLab Now you use that to ...

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No you cannot use a Vin or VU pin as a GPIO pin which can be controlled by a program. Vin can be used as an input for 5V battery or as a 5V output when NodeMCU is powered by USB.(Expect on NodeMCU v3 by Lolin). To get 5V to power external 5V sensors you can use Vin pin(on Lolin NodeMCU v3 use VU to get 5V output instead of Vin). To control 5V sensor with ...

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